I got ~100 subscribers in my first week. This is what worked, and what did not.
I've been a classic victim of writing blogs and then getting stuck on 3 likes from friends and family. As someone who loves to write, but hates to promote, this has been a major factor why I was apprehensive of trying Substack.
But then I gave in. Created a fresh account. Chose a niche I am deeply passionate about. Something where I could think of next 10 articles from day 1. And before posting my first article, I actually wrote the complete drafts for the first 3.
I am a designer, so I do have a pretty good sense of brand and aesthetics compared to most folks. I tried to capitalize on this and built a proper brand system for cover images, logos etc.
Now that the base was set.
I went in and posted 3 articles in 3 days. Yes, this might irk some Substack purists. But my logic was simple. If someone lands on my profile, they should have enough content to make a decision that, "yes, this guy writes quality stuff that will make me click on the orange button."
I used notes liberally, like posting 2-3 a day for the first 3 days and now down to 1 per day. Once the initial subscribers started coming in, I did a quick analysis on their profiles to figure out what kind of notes they'd be into. I think this part is important when you have a small sample size. Although my original blog is not directly related to my notes, but the initial deviation could be important to go from first 10 to first 50 subscribers.
After that, I went back to notes closer to my niche. Essentially go a little mass market to get the initial traction rolling and then specialize.
Also, super important, engage with others. I cleared up my Sunday afternoon and went through some posts of the people who kept showing up on my feed, and left some thoughtful comments. That definitely helped in getting profile views where I had already established myself with three posts with nice graphics and some notes with decent engagement. This does the trick.
Again, this is purely anecdotal from one week of experience, but I've been pleasantly surprised by Substack and the community engagement here.